1820819864 has 16 divisors (see below), whose sum is σ = 3493434120. Its totient is φ = 889237440.

The previous prime is 1820819857. The next prime is 1820819899. The reversal of 1820819864 is 4689180281.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2646197 + ... + 2646884.

Almost surely, 2^1820819864 is an apocalyptic number.

It is an amenable number.

1820819864 is a deficient number, since it is larger than the sum of its proper divisors (1672614256).

1820819864 is a wasteful number, since it uses less digits than its factorization.

1820819864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5293130 (or 5293126 counting only the distinct ones).

The product of its (nonzero) digits is 221184, while the sum is 47.

The square root of 1820819864 is about 42671.0658877886. The cubic root of 1820819864 is about 1221.1124547992.

The spelling of 1820819864 in words is "one billion, eight hundred twenty million, eight hundred nineteen thousand, eight hundred sixty-four".